From: Trond Myklebust <trondmy@gmail.com>
To: linux-nfs@vger.kernel.org
Subject: [PATCH 17/19] pNFS: Don't send LAYOUTGET on OPEN for read, if we already have cached data
Date: Wed, 30 May 2018 14:05:51 -0400 [thread overview]
Message-ID: <20180530180553.38769-18-trond.myklebust@hammerspace.com> (raw)
In-Reply-To: <20180530180553.38769-17-trond.myklebust@hammerspace.com>
From: Trond Myklebust <trond.myklebust@primarydata.com>
If we're only opening the file for reading, and the file is empty and/or
we already have cached data, then heuristically optimise away the
LAYOUTGET.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
fs/nfs/pnfs.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 8c6ce63f5ed0..5fc4d84d9326 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1996,6 +1996,11 @@ static void _lgopen_prepare_attached(struct nfs4_opendata *data,
struct nfs4_layoutget *lgp;
struct pnfs_layout_hdr *lo;
+ /* Heuristic: don't send layoutget if we have cached data */
+ if (rng.iomode == IOMODE_READ &&
+ (i_size_read(ino) == 0 || ino->i_mapping->nrpages != 0))
+ return;
+
lo = _pnfs_grab_empty_layout(ino, ctx);
if (!lo)
return;
--
2.17.0
next prev parent reply other threads:[~2018-05-30 18:06 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-30 18:05 [PATCH 00/19] Layoutget on OPEN Trond Myklebust
2018-05-30 18:05 ` [PATCH 01/19] pnfs: Remove redundant assignment from nfs4_proc_layoutget() Trond Myklebust
2018-05-30 18:05 ` [PATCH 02/19] pnfs: Store return value of decode_layoutget for later processing Trond Myklebust
2018-05-30 18:05 ` [PATCH 03/19] NFS4: move ctx into nfs4_run_open_task Trond Myklebust
2018-05-30 18:05 ` [PATCH 04/19] pnfs: Add layout driver flag PNFS_LAYOUTGET_ON_OPEN Trond Myklebust
2018-05-30 18:05 ` [PATCH 05/19] pnfs: refactor send_layoutget Trond Myklebust
2018-05-30 18:05 ` [PATCH 06/19] pnfs: move allocations out of nfs4_proc_layoutget Trond Myklebust
2018-05-30 18:05 ` [PATCH 07/19] pnfs: Add conditional encode/decode of LAYOUTGET within OPEN compound Trond Myklebust
2018-05-30 18:05 ` [PATCH 08/19] pnfs: Move nfs4_opendata into nfs4_fs.h Trond Myklebust
2018-05-30 18:05 ` [PATCH 09/19] pnfs: Change pnfs_alloc_init_layoutget_args call signature Trond Myklebust
2018-05-30 18:05 ` [PATCH 10/19] pnfs: Add LAYOUTGET to OPEN of a new file Trond Myklebust
2018-05-30 18:05 ` [PATCH 11/19] pnfs: Add LAYOUTGET to OPEN of an existing file Trond Myklebust
2018-05-30 18:05 ` [PATCH 12/19] pnfs: Stop attempting LAYOUTGET on OPEN on failure Trond Myklebust
2018-05-30 18:05 ` [PATCH 13/19] pnfs: Add barrier to prevent lgopen using LAYOUTGET during recall Trond Myklebust
2018-05-30 18:05 ` [PATCH 14/19] pnfs: Fix manipulation of NFS_LAYOUT_FIRST_LAYOUTGET Trond Myklebust
2018-05-30 18:05 ` [PATCH 15/19] NFSv4/pnfs: Ensure pnfs_parse_lgopen() won't try to parse uninitialised data Trond Myklebust
2018-05-30 18:05 ` [PATCH 16/19] NFSv4/pnfs: Don't switch off layoutget-on-open for transient errors Trond Myklebust
2018-05-30 18:05 ` Trond Myklebust [this message]
2018-05-30 18:05 ` [PATCH 18/19] pnfs: Don't call commit on failed layoutget-on-open Trond Myklebust
2018-05-30 18:05 ` [PATCH 19/19] pnfs: Don't release the sequence slot until we've processed layoutget on open Trond Myklebust
2018-05-30 20:10 ` [PATCH 04/19] pnfs: Add layout driver flag PNFS_LAYOUTGET_ON_OPEN Olga Kornievskaia
2018-05-31 12:40 ` Trond Myklebust
2019-09-06 20:17 ` Olga Kornievskaia
2018-05-30 18:25 ` [PATCH 00/19] Layoutget on OPEN Olga Kornievskaia
2018-05-30 18:36 ` Trond Myklebust
2018-05-30 18:37 ` Olga Kornievskaia
2018-05-30 19:27 ` Olga Kornievskaia
2018-05-30 19:29 ` Olga Kornievskaia
2018-05-30 19:47 ` Olga Kornievskaia
2018-05-30 22:33 ` Trond Myklebust
2018-05-31 18:59 ` J. Bruce Fields
2018-06-01 0:28 ` Trond Myklebust
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